1. Field of the Invention
The present invention relates to the field of static land markers and, more specifically, to yieldable posts which are particularly useful in ski areas, such as for ski gates or slalom course markers. In addition, the present invention is especially useful for safety markers, ski lift line delineators, boundary identifiers and the like.
2. Description of the Prior Art
It is known in the prior art to anchor poles in the earth by various means. For example, U.S. Pat. No. 3,969,853 by Deike discloses a torque fin ground anchor with tilted fins which is driven into the ground in a relatively permanent installation for retaining a rigid post in place. U.S. Pat. No. 3,302,347 by Jackson describes an anchor with retaining flukes which is driven into the ground but which can accommodate flexing of its main shaft.
The prior art has recognized the need for flexible ski posts to minimize injury when a skier runs into a post. Thus, some prior art has developed mechanisms to anchor a slalom pole while permitting a certain amount of flexibility to it. An example is U.S. Pat. No. 4,702,639 by Hinterholzer which discloses a rigid slalom post with a flange rotatable in a radial plane to hold the post in the snow. A degree of flexibility is obtained by interconnecting upper and lower post segments by rubber-elastic elements or bushings. However, slalom poles, as taught in Hinterholzer, are expensive to fabricate while positioning of the lower, anchored elements so they are not an additional hazard to skiers is obviously critical but difficult to maintain as snow levels change. Further, when a skier hits either of the relatively rigid post segments, there is a danger of injury to that skier.
Another example of a rigid slalom post with a single pivot point is discussed in U.S. Pat. No. 4,491,438 by Berutti. The upper and lower post segments of Berutti are interconnected by a pivot joint using a complex of discs and coaxial springs thereby demanding relatively expensive posts. In addition, Berutti likewise suffers from the disadvantages associated with the need to locate the pivot joint so that it resides in close proximity to the surface of the snow or else it hazards serious injury to the skiers, as does the rigidity of the pole elements.
A need remains in the art for a post that is safe to use as a marker throughout a ski area and which avoids the expense and safety hazards of contemporary ski poles. Furthermore, the prior art devices are not well suited to accommodating the variety of snow depths at certain parts of the year because that snow depth sometimes varies greatly. Therefore, there is a need for a more flexible post application that is relatively independent of the snow depth variations.
Still further, contemporary ski gates are awkward to use for training purposes and are not adaptable for a variety of training exercises and programs. Normally, a ski instructor, student and/or competitor must arrange availability of an existing slalom course for training. Also, contemporary slalom gates are simply not well suited for training exercises in other ski activities. Additionally, servicing a full length regulation course or performing a single trail closure within the existing art is a multiple person task placing a considerable burden on the operator carrying the prior art devices.